1. Field of Invention
The present invention relates to the assigning of IP addresses to internal components of a modular network system.
2. The Background Art
The widespread use and acceptance of the Internet has generated much excitement, particularly among Competitive Local Exchange Carriers (“CLECs”), among others, who see advantages in networking their voice and data communications. A CLEC is a term coined for the deregulated, competitive telecommunications environment, envisioned by the Telecommunications Act of 1996. CLECs compete on a selective basis for local exchange service, as well as long distance, Internet access, and entertainment. They typically lease local loops from the incumbent Local Exchange Carriers (“LEC”) at wholesale rates and then resell to end users at a discounted price. CLECs often have customer premise equipment (CPE) on site. CPEs include, but are not limited to, devices such as CSU/DSUs, modems, Integrated Access Devices (IADs) and ISDN terminal adapters, required to provide an electromagnetic termination for wide-are network circuits before connecting to the router or access server. CPEs were historically provided by the telephone company, but are now typically provided by the customer (CLEC).
CPEs are often comprised of a manufacturer's proprietary system. Thus in order to connect, set up and maintain CPEs on a computer network, a computer network specialist trained and certified in the manufacturer's proprietary system was needed. Due to the nature and importance of keeping the computer network online and working properly, the computer network specialist was often a permanent employee of the business entity installing and maintaining the CPEs for the CLEC.
However many businesses simply do not desire a system so complex that a it requires having a computer network specialist on staff full time. Hence there is a need to be able to automatically configure CPEs with a minimum of human interaction. One aspect of such an automatic configuration is the assigning of IP addresses automatically to the CPEs after the CPEs power up. An IP address is usually a 32-bit address assigned to hosts using TCP/IP. An IP address belongs to one of five classes (A, B, C, D, or E) and is written as 4 octets separated by periods (dotted decimal format). Each address consists of a network number, an optional subnetwork number, and a host number. The network and subnetwork numbers together are used for routing, while the host number is used to address an individual host within the network or subnetwork. A subnet mask is used to extract network and subnetwork information from the IP address.
Referring to FIG. 1 will aid in understanding a known method of assigning an IP address to a CPE. A device A 100 is shown with a serial connector 110. A device B 120 is also shown with a serial connector 130. Device A 100 may be a router. Device B may be a CPE. Upon powering up the system, device B 120, may use an algorithm known as a Serial Line Address Resolution Protocol (SLARP) to assign itself an IP address. The SLARP protocol 140 is shown installed in device B. One example of the algorithm the SLARP protocol uses for assigning IP addresses is shown in FIG. 2. Referring to FIG. 2, device B powers up at act 210. Device B requests A's IP address at act 220. The algorithm determines whether the last octet in A's IP address is a one (1) at query 230. If it is a one (1), the algorithm adds one (1) to the last octet of A's IP address and assigns that IP address to device B at act 240. The algorithm ends at act 280. If the algorithm determines that the last octet of A's IP address is not one (1), then the algorithm determines whether the last octet is two (2) 250. If the last octet is two (2), then the algorithm subtracts 1 from the last octet, and assigns that IP address to device B at act 260. The algorithm ends after that act 280. If the last octet of A's IP address is neither a one (1) or a two (2), then the algorithm does not assign an IP address to device B shown at act 270.
As can be seen, the algorithm described in FIG. 2 can only work with an IP address where the last octet is either a one (1) or a two (2). For example, if the IP address for device A is 132.222.19.1, then the IP address assigned to device B is 132.222.19.2 pursuant to the algorithm shown on FIG. 2. If the IP address for device A is 132.222.19.2, then the IP address assigned to device B is 132.222.19.1. If the last octet of A's IP address is anything other than one (1) or two (2), then the algorithm cannot assign an IP address to B.
Thus, there is a need to be able to automatically configure CPEs. Part of that automatic configuration includes assigning IP addresses to the CPEs, however, assigning an IP address restricted by the last octet to either one (1) or two (2) is very limiting. Thus there is also a need to be able to automatically assign IP addresses to CPEs with a range in the last octet greater than one (1) or two (2).